To obtain an optical module that oscillates green laser light of a wavelength 530-nm band, infrared laser light of a 1060-nm band is used as fundamental laser light, and the wavelength of the fundamental laser light is converted by a wavelength converting device in many cases. Therefore, the optical module that oscillates green laser light generally includes a solid-state laser device that oscillates fundamental laser light, a pump light source that pumps the solid-state laser device, and a wavelength converting device.
According to the optical module, when a light loss in a laser resonator that constitutes the solid-state laser device is increased, a heating value of the optical module is increased and the performance thereof is degraded. Therefore, to achieve an output increase of the optical module, it is essential to reduce the light loss in the laser resonator, and thus it is necessary to enhance alignment precision between an optical axis of the solid-state laser device and that of the wavelength converting device.
Although it is not an optical module of the above type, according to an integral semiconductor laser light source/optical waveguide apparatus described in Patent Document 1, for example, a distance from a surface of an optical waveguide device in which an optical waveguide is formed to a center axis of a light-incident end of the optical waveguide, and a distance from a surface of a semiconductor laser to a center axis of a light-emitting end are set equal to each other. With this configuration, a position of an axis of the optical waveguide device and a position of an axis of the semiconductor laser can be precisely set. According to this optical waveguide apparatus, the optical waveguide device and the semiconductor laser are placed side-by-side on a common board and fixed thereto by a bonding material such as an adhesive and solder.
In an electro-optical system described in Patent Document 2, a first submount and a second submount are provided in a separated manner, a secondary heat sink is mounted on the first submount, an active gain medium (such as laser and crystal) is provided such that the active gain medium protrudes over the first submount from the secondary heat sink, and a pump source (a laser diode) for the active gain medium is mounted on a sidewall of the second submount on the side facing the first submount. By placing the active gain medium and the pump source in this manner, a distance between the active gain medium and the pump source becomes precise. In the mode specifically described in the Patent Document 2, one end of the active gain medium is engaged with a recess formed on an upper surface of the second submount.
Patent Document 1: Japanese Patent Application Laid-open No. H05-289132
Patent Document 2: Japanese Patent Application Laid-open No. 2001-085767